Mutation of Flagellar Master Regulator FlhDC Can Prevent Virulence Capability in Dickeya Dadantii 3937
Mentor 1
Ching-Hong Yang
Location
Union Wisconsin Room
Start Date
29-4-2016 1:30 PM
End Date
29-4-2016 3:30 PM
Description
Dickeya dadantii 3937 is a globally dispersed phytopathogen which causes disease in a wide range of host plants, including many economically important vegetables such as potato, tomato, and chicory. Chemotaxis and motility contribute to the initial infection by allowing the pathogen to enter into the plant apoplast. Once in the apoplast, D. dadantii uses the type III secretion system (T3SS) to suppress host defense responses, and secretes pectate lyase (Pel) to degrade the plant cell wall. FlhDC is the master regulator in flagellar assembly genes, which controls the expression of genes that encode proteins for the outer subunits of the flagellum, chemotaxis, and the flagellar motor. In this study, we observed attenuated phenotypes in terms of T3SS gene expression, Pel production, swimming motility, and virulence in Chinese cabbage (Brassica campestris) and African violet (Saintpaulia ionantha) when flhDC was deleted in D. dadantii. In addition, restoring T3SS and Pel but not swimming was not able to complement the overall virulence of the flhDC mutant in the host plant, suggesting that swimming motility, Pel production and T3SS gene expression are essential in determining the full virulence of D. dadantii 3937 in host plants.
Mutation of Flagellar Master Regulator FlhDC Can Prevent Virulence Capability in Dickeya Dadantii 3937
Union Wisconsin Room
Dickeya dadantii 3937 is a globally dispersed phytopathogen which causes disease in a wide range of host plants, including many economically important vegetables such as potato, tomato, and chicory. Chemotaxis and motility contribute to the initial infection by allowing the pathogen to enter into the plant apoplast. Once in the apoplast, D. dadantii uses the type III secretion system (T3SS) to suppress host defense responses, and secretes pectate lyase (Pel) to degrade the plant cell wall. FlhDC is the master regulator in flagellar assembly genes, which controls the expression of genes that encode proteins for the outer subunits of the flagellum, chemotaxis, and the flagellar motor. In this study, we observed attenuated phenotypes in terms of T3SS gene expression, Pel production, swimming motility, and virulence in Chinese cabbage (Brassica campestris) and African violet (Saintpaulia ionantha) when flhDC was deleted in D. dadantii. In addition, restoring T3SS and Pel but not swimming was not able to complement the overall virulence of the flhDC mutant in the host plant, suggesting that swimming motility, Pel production and T3SS gene expression are essential in determining the full virulence of D. dadantii 3937 in host plants.
